Inductance unit



Dec. 7, 19 48 E. o. PETERSON ETAL INDUCTANCE UNIT Filed July 10, 1944 Inventors. I Eric; 'O.Pet er-son, David Lwrighb, Henr T Heaton Then" AtLorn Patented Dec. 7, 1948 UNITED STATES PATENT OFFICE INDUCTANCE UNIT Eric 0. Peterson, Bridgeport, David I. Wright, Westport, and Henry T. Heaton, Milford, Com, assignors to General Electric Company, a corporation of New York Application July 10, 1944, Serial No. 544,288

' 2 Claims.

Our invention relates to radio apparatus and it has for its object to provide a new and improved radio frequency inductance unit.

It is another object of our invention to provide a new and improved radio frequency transformer.

One of the features of our invention is the provision of a molded body of insulating material constituted by separable portions which, when united, form a substantially closed chamber in which the magnetic core and winding of an inductance unit may be supported. Terminals molded in the insulating material provide a conducting path between the ends of the inductance coil and external connections to the coil, as well as means for mounting other components of the radio apparatus. When two such inductance units are mounted within a metallic member, the coils of the units are shielded from fields external of the metallic member and are coupled by the metallic member which functions as a link coupling.

It is still another object of our invention to provide a new and improved unitary high frequency inductance unit which is relatively simple to manufacture and assemble and may be constructed at relatively low cost.

The features of our invention which we believe to be novel are set forth with particularity in the appendedclaims. Our invention itself, however, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing in which Fig. l is a sectional view of one of the inductance units used in our transformer arrangement; Fig. 2 is an exploded view of the inductance unit tudinal slots 8 into which fit a pair of projection ID on the magnetic cups 1, 8. The magnetic core comprising the cups 7, 8 preferably is formed of a molded or compressed composition comprising powdered iron particles and the projections ill, by fitting into the slots 9-, prevent movement of the core body within the chamber 8. Each of the cups 1, 8 is likewise provided with a centrally located aperture II and a recessed portion i2 surrounding the aperture Ii in which her 3 likewise has a plurality of slots l9 extending from the left-hand end of each of the terminals I! to the central opening within the member 3,

of Fig. 1; and Fig. 3 is a view, partly in section,

rable parts 2, 3 adapted to fit together in interlocking engagement, the member 2 being provided with a flange 4 which surrounds a raised portion 5 in the molded part 3. When interfitted. the members 2, 3 form a substantially closed chamber 0 in which is disposed a magnetic core, the magnetic core comprising two identical cuplike members 1, 8. The chamber 6 is substanthese slots being provided to accommodate the lead It of the inductance coil. Each of the terminals ll, moreover, is provided throughout its length with a plurality of notches 20 by means of which the wrapping of a wire around the conductor l1 and its soldering thereto are expedited. Moreover, the holes [8 in the body member 2 are substantially larger than the circumference of the terminals 11 so that the ends of these terminals, even when the leads l6 are wrapped thereabout and soldered thereto, fit into the holes l8 without injury to the leads.

The molded member 2 likewise is provided with a longitudinal aperture or passageway 2! which extends from the chamber 8 to the left-hand end of the member 2 and has a diameter slightly larger than the diameter of a magnetic tuning member or slug 22, which is adapted to pass through both the hole H in the magnetic core member I and the coil form l3. Formed integrally with the tuning slug 22 is a metallic shaft portion which comprises the screw or threaded member 23, which extends through an aperture 24 at the end of passageway 2| in molded member 2. In order to maintain the tuning slug 22 in an adjusted position, the body member 2 is provided with a rectangular aperture or slot 25 lying below and connected to the longitudinal passageway 2|, and a resilient metallic member tially cylindrical in form and each of the molded members 2, .3 is provided with a pair of longi- 26 is adapted to fit in the slot 25. The member 28 at one end has an arm 2'! in which is an apersee ers ture of substantially the same diameter as screw 23 and which is adapted to slide over the screw 23. At its other end, the member to is ill-shaped and has a yoke 28 which likewise engages the screw 23. The hole in the arm H is eccentric with the yoke 28 so that the yoke 28 presses against the screw 23 and tends to rotate the member 26 on the screw 23, the member 28 pivoting about the hole in the arm 2i. As a result of this structure, when the member to is placed within the slot 25, it presses against the bottom wall of the slot and the yoke 28 presses against the screw 23. The member 26 thus engages the threads on screw 23 and tends to resist longitudinal movement of the screw it in the aperture 2i, maintaining the tuning slug in an adjusted position.

The molded member 3 is also provided with a I plurality of tapped holes 29 and the member 2 is provided with corresponding holes it so that the molded body may be held together by means of screws to form a unitary inductance member which is easily adapted to incorporation into a radio chassis. To this end, the member 2 is provided with a plurality of tapped holes 8!] by means of which the unitary inductance member may be supported.

in certain uses, it may be desirable to form an inductance unit which does not include the magnetic core members or cups l, 8. To this end, the members 2 and 3 are provided, respectively, with the aligned recesses 82, 5323 having a diameter substantially equal to the diameter of the coil form B3. in such installations, a coil form having a length greater than that shown in Figs. 1 and 2 is employed and the ends of the coil form lit in the recesses'dil, 33.

The composite inductance unit described above is especially well adapted for use in the formation of transformers for high frequency currents. Fig. 3 illustrates such an application in which a pair of the coil assemblies are placed within a conductive member or shield 36 and the coil as semblles i are secured to the member by means of a plurality of screws 35 which engage the threads ct holes 35. The metallic shield is likewise provided with a pair of apertures, not shown, through whichproject the ends of the tuning slug adjusting screws 23. The bottom end of the shielded member 3% is closed by means of a wall 36 of insulating material through which project the ends of the terminals ill. in this con= struction, the member 3t functions both to shield the windings within the coil assemblies i from electromagnetic fields external to the member it and also to couple the windings within the coil assemblies. The degree of coupling may be ad= justed by means of a transverse wall or separating shield 37 lying between adjacent coil as semblies i. The shield ill is or" a height and of the necessary conductivity to provide a required degree of coupling between the coil assemblies. Such a transformer is especially well adapted for use in the intermediate frequency circuits of radio receivers, and in such installations the iiidivldual windings may be resonated by means of capacitances 38 connected between the terminals i1 and shunting the windings within the coil assemblies i'. The individual units may be tuned to a desired frequency by movement of the screws 23 to adjust the tuning slugs within the coil wind ings.

The shield can it may be of any suitable non= Gill magnetic metal, such as aluminum. The separating shield 3'! likewise may be iormed of aluminum or may be formed 01 a dielectric material. such as a molded synthetic resin, which is coated with a suitable conductive material, such as, for example, silver. In the transformer arrangement, the windings l4 within the coil assemblies 9 are arranged with parallel axes and the shield member 84 functions as a one-turn link coupling between these windings. The separating shield 31 functions as a short-circuit .over a portion of this turn and its height and conductivity control the degree of couphng.

It is thus seen that our invention provides a sturdy and compact coll assembly which is especially well adapted ior use in radio frequency circuits. The units may be used singly as inductance units, filters or wave traps, or as a portion of a resonant means in oscillator circuits. They may be employed in pairs, together with a link coupling means, for radio frequency and intermediate frequency transformer arrangements. each unit being composed of a minimum number of easily formed parts. Their construction minimites assembly and tuning operations.

While we have shown a particular embodiment of our invention, it will of course be understood that we do not wish to be limited thereto since various modifications may be made, and we con template by the appended claims to cover any such modifications as fall within the true spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

l. A transformer arrangement for high irequency currents comprising a plurality of housing members, each of said members comprising insulating means forming a substantially closed chamber, a magnetic core supported within said chamber, a winding disposed within said core, and a one-turn link coupling for said windings within said chambers comprising a conductive body surrounding said members ior shielding said windings from electromagnetic fields external to said body.

2. A transformer arrangement for high frequency currents comprising a plurality oi housing members, each of said members comprising in-- sulatlng means forming a substantially closed chamber, a magnetic core supported within said chamber, a winding disposed within said core, a conductive body surrounding said members for Shielding said windings from electromagnetic fields external to said body and for coupling said windings within said chambers, and a conductive shield ,inexnber disposed between said housing members for controlling the amount of said coupling.

ERIC 9. PON. DAVID I. WRIGHT. TENRI T. HEATON.

' REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date l, 457, 784 Maurer June 5, 1923 2, 149, 848 Lampel Mar. '7, 1939 a, 180,413 Harvey Nov. 21, 1939 2,253, 652 James Oct. it, 1941 2, see, 205 Zepp Nov. 23, 32.943 

